1. Field of the Disclosure
The present invention relates to a method of finishing a component. In particular, the present invention may be applied to the finishing of a blade for a gas turbine engine comprising adaptive machining of the blade's aerodynamic surface.
2. Description of the Related Art
Gas turbine engines comprise various precision engineered components. The precise dimensions of these components are crucial in determining the performance of the component, and thus the performance of the gas turbine engine, for example in terms of specific fuel consumption. Thus, many components need to be manufactured to very tight tolerances.
Such components that must be manufactured to a high degree of accuracy include aerofoil-shaped components in a gas turbine engine, including the various rotating blades and stationary vanes. The profile of such aerofoil components is critical in determining the performance of the engine.
Presently, the final step in manufacturing many such aerofoil components involves manually dressing the components. In other words, a skilled human operator holds a blade against a polishing or dressing emery belt to remove any unwanted features, such as features that may have resulted from a casting process used in an earlier manufacturing step. In this way, the human operator uses their skill and judgement to manually finish the blade by eye.
Even though the human operators are highly skilled, there is potential for the finished blades to contain inaccuracies, imperfections, or inconsistencies. For example, the human operators may remove too little or too much material from a certain part of the blade, for example when attempting to remove a witness feature resulting from a casting process. Such a blade may still be within inspection tolerance, but may contain minor imperfections on the surface that may have a significant detrimental impact on the performance of the blade. Furthermore, the process is extremely labour intensive and time consuming, and thus expensive. In addition, it is possible that the repetitive nature of the manual finishing of blades may lead to health problems for the operators.